North Pacific Right Whale
(Eubalaena japonica)Printer Friendly

Did You Know?

Early whalers captured a calf first, knowing the mother was unlikely to escape since female right whales have a strong protective maternal instinct.

General Description

The North Pacific right whale is a large baleen whale. Baleen whales are characterized by having baleen plates for filtering food from water, rather than having teeth. The females are larger than the males and can grow up to 55 feet. The North Pacific right whale has a very large head, approximately one-quarter of its body length, with strongly arched jaws. There are light, wart-like spots on its head called callosities. It has a wide body, lacks a dorsal fin, and is mostly black with some white patches on its underside. Right whales weigh up to 2,000 lb at birth and up to 220,000 lb at maturity, with a life span over 50 years. Two populations, or stocks, of North Pacific right whales are currently recognized one in the western North Pacific off Russia and the other in the eastern North Pacific off Alaska.

Right whales are sometimes confused with bowhead whales. Right whales typically have the obvious wart-like callosities on their heads, while the skin of bowhead whales is usually smooth. The North Pacific right whale is one of the rarest marine mammal species in the world due to heavy exploitation by commercial whalers prior to 1949.

Similar Species

The North Atlantic right whale (Eubalaena glacialis) and southern right whale (Eubalaena australis) are other species of right whale. The geographic ranges of the three different species of right whales do not overlap, so they never meet in their ocean travels. All species of right whales are endangered and internationally protected from whaling since 1949.

Life History

Reproduction and Growth

Female right whales generally give birth to their first calf at 9-10 years of age. Pregnancy lasts approximately 1 year. The calf is 13-15 feet and weighs up to 2,000 lb at birth and will nurse for a year. Mature right whales grow to 45-55 feet and up to 220,000 pounds (100 metric tons). Populations of right whales grow slowly because it takes a long time for female right whales to reach sexual maturity and only give birth to a single calf.

Foraging Ecology

North Pacific right whales consume zooplankton, tiny animals floating in the water column (e.g., copepods and krill), by using a technique called "skimming." With mouths open, they swim through patches of zooplankton, catching the tiny animals on their baleen. Baleen is a comb-like filtering structure made out of the same substance as hair and nails (the protein keratin). Most feeding is believed to occur between spring and fall.

Migration

The migration patterns of the North Pacific right whale are unknown. It is believed that they feed during the summer in high latitudes and move to more temperate areas for the winter.

Review of more than 3,600 North Pacific right whale calls detected by passive listening devices between 2000–2006 strongly suggests that the whales migrate into the southeast Bering Sea in late spring and remain until late fall. The earliest calls were heard in late May and the latest in December. The peak calling period was July through October. Most calls were detected from shallow waters over the continental shelf, sites within the designated Critical Habitat area encompassing the southeastern Bering Sea and Gulf of Alaska.

Behavior

Right whales spend most of their lives underwater. We gain clues about their sub-surface behavior from underwater microphones (hydrophones), data tags, and from whale dive times. Right whales have been seen returning to the surface with mud on their heads, indicating they swam to the ocean’s bottom during a dive.

At the surface, right whales exhibit a variety of behaviors:

breaching (jumping out of the water)

fluking (lifting the tail out of the water)

nursing

spy hopping (lifting the head out of the water)

logging (resting)

skim feeding (feeding at or just below the water’s surface)

posturing (arching its back bringing both flukes and head out of the water)

surface active group behavior (two or more whales socializing at the surface).

The first five behaviors are exhibited by many whale species; the last three are less common.

Range and Habitat

Whaling records indicate that right whales were once abundant throughout the eastern North Pacific and Bering Sea during the summer months in the 19th and early 20th centuries. As a result of international protection from hunting in 1935, the right whale population was growing by 1960, although large illegal catches by Soviet whalers during the 1960s in the eastern North Pacific and Bering Sea crippled recovery. The right whales in the eastern North Pacific are only a remnant of the former population and may not fully occupy the same range they did two centuries ago. While the importance of other historical habitats in the eastern North Pacific is unknown, modern sightings of right whales have led to areas of the southeastern Bering Sea and Gulf of Alaska being designated as critical habitat for North Pacific right whales.

The North Pacific right whale is distributed from Baja California to the Bering Sea with the highest concentrations in the Bering Sea, Gulf of Alaska, Okhotsk Sea, Kuril Islands, and Kamchatka area. They are primarily found in coastal or shelf waters but sometimes travel into deeper waters. In the spring through the fall their distribution is dictated by the distribution of their prey. In the winter, pregnant females move to shallow waters in low latitudes to calve; the winter habitat of the rest of the population is unknown.

Alaska Focus

Heavily impacted by whaling, the eastern population of whales that occur off the west coast of Alaska currently has an abundance of only a few tens of animals, making it the most endangered marine mammal population in U.S. waters.

Between the late 1960s and the mid-1990s sightings of right whales in the eastern North Pacific were rare, widely scattered, and almost always involved solitary animals.

Significant sightings occurred in the summer of 1997 when a group of four animals was reported in the southeastern Bering Sea and in 2002 with the first confirmed sighting of a calf in decades. In 2004 a concentration of whales was found that included a minimum of 17 whales. Additionally, a whale which is thought to be a sub-adult animal was observed in Uganik Bay, Alaska in December 2011, being the first modern record of the species on the western side of Kodiak Island and one of the few sightings that has occurred in near-shore waters.

Detections of right whales have been very rare in the Gulf of Alaska, even though large numbers of whales were caught there in the 1800s. From 2004 to 2006, four sightings occurred in the Barnabus Trough region on Albatross Bank, south of Kodiak Island. This area represents important habitat for the relic population of North Pacific right whales, and a portion of this area was designated as critical habitat under the US Endangered Species Act. For a map of the North Pacific Right Whale Critical Habitat area established in 2006 and 2008, visit
http://www.nmfs.noaa.gov/pr/pdfs/criticalhabitat/northpacificrightwhale.pdf.

NOAA Fisheries continues to conduct research on the North Pacific right whale to learn more about its population status.

Status, Trends, and Threats

Status

An accurate estimate of the current abundance of the North Pacific right whale is not available, although the number of whales in the eastern population is considered to be in the 10s of animals. A reliable estimate of the number of whales in the western population is not available. The species is currently listed as endangered under the Endangered Species Act (ESA).
To learn more, visit the ADF&G Special Status page for North Pacific right whale.

Trends

The current population trend is unknown. Over 11,000 individuals likely occupied the North Pacific prior to whaling.

Threats

Threats to the North Pacific right whale potentially include inbreeding depression and low population density effects, collisions with ships and entanglement in fishing gear, pollution, degradation of feeding habitat (e.g., through effects of pollution of zooplankton), human disturbance (e.g., ships and other underwater noisemakers) and climate change and resultant changes in food supply. The potential impact on right whales, and other listed species, from proposed oil and gas development in the North Aleutian Basin should be monitored carefully; including seismic surveys conducted during the early stages of development.

Fast Facts

Size
Length 45-55 ft., weight at birth up to 2,000 lb, weight at maturity up to 220,000 lb

Remarks
The eastern North Pacific right whale population found off Alaska in summer is the most endangered of all large whales. A significant sighting occurred in the southeastern Bering Sea off Alaska in 1996 when a group of four whales were reported; the most North Pacific right whales seen together in almost 30 years. In 2004 an astonishing concentration of whales was found that included a minimum of 17 whales.

Did You Know?

Whalers gave the North Pacific right whale its name based on it being the "right whale" to hunt: it was large, slow and floated at the surface when killed.

Right whales consume some of the smallest prey and have some of the longest baleen, up to 8 feet, of any baleen whale (Baleen whales are filter feeds and do not have teeth).

Right whales are one of the rarest marine mammal species in the world, with the eastern North Pacific right whale population found off Alaska in summer the most endangered of all large whales.

Right whales are an endangered species. Their populations remain small even though commercial hunting of right whales stopped in 1949.

Right whales weigh up to 2,000 lb at birth and up to 220,000 lb at maturity.

Right whales are easy to identify because they have no dorsal (back) fin.

Early whalers captured a calf first, knowing the mother was unlikely to escape since female right whales have a strong protective maternal instinct.

Neither Japan nor the Soviet Union signed the 1931 agreement to stop right whale commercial hunting and continued to legally hunt whales until the enactment of the 1949 international regulations.

Uses

Commercial Whaling

Right whales were a favorite target of whalers in the 1800s and 1900s. They are very slow swimmers and float after being killed. They were harvested for their blubber, baleen, and oil. Commercial hunting of right whales has been illegal since 1949.

Viewing

If you see a right whale consider yourself very fortunate as sightings of this endangered species are extremely rare. North Pacific right whales are managed by the National Marine Fisheries Service (NMFS) under the National Oceanic and Atmospheric Administration (NOAA Fisheries) and any information about sightings should be promptly reported to NOAA Fisheries. Whale viewing is a popular activity in Alaska and can have serious impacts on whale populations if not conducted properly. Most viewing occurs where whales congregate at concentrated food sources that are critical to their survival. During this activity it is imperative to stay at a minimum of 100 yards away from whales to avoid the dangers of ship and prop strikes. Pursuit of whales is prohibited by law. Managing human behavior around viewing activities is important to the continued health of whale populations.

Management

North Pacific right whales are managed by NMFS. They were first protected by the 1931 international or multi-national Convention for the Regulation of Whaling, which took effect in 1935. However, neither Japan nor the Soviet Union signed this agreement, so it was theoretically still legal for them to kill right whales. In 1949, the International Convention for the Regulation of Whaling protected right whales from commercial whaling. This species also falls under the legislation of the U.S. Marine Mammal Protection Act and the U.S. Endangered Species Act.

Research

ADF&G has contributed funding to the acoustic monitoring of North Pacific right whales. In August 2004, the Cetacean Assessment and Ecology Program (CAEP) at the National Marine Mammal Laboratory initiated a North Pacific right whale tagging project. This is a collaborative study with the whale-tagging group at the Greenland Institute for Natural Resources in Copenhagen, Denmark. Three main questions are being addressed by this study:

Where do North Pacific right whales go in winter?

What migratory route do they take to get to their wintering grounds?

Do right whales found in the southeast Bering Sea in summer also use other feeding areas in Alaska?

The project should provide information about specific habitat use in the Bering Sea, with the potential for investigating the oceanographic conditions of those areas.

More Resources

General Information

National Marine Mammal Laboratory: a branch of the NMFS Alaska Fisheries Science Center that conducts research on marine mammals with a focus on marine mammals off the coasts of Alaska, Washington, Oregon, and California

Marine Mammal Commission: an independent agency of the US Government responsible for oversight of marine mammal conservation policies and programs carried out by federal agencies